Research up-date as of February 19, 2016:

At the conclusion of our study, with data from 31 classrooms and 680 students, we asked the following questions:>br />

Is there an effect of alignment: Do students in the high-aligned condition outperform students in the low-aligned condition?

Is there an interaction between alignment and prior knowledge: Is the high-aligned condition especially helpful for low prior knowledge students?

Using a mixed effects logistic regression model, we found a significant effect of alignment, such that controlling for pre-test, grade, and school SES, students in the high-aligned condition were significantly more likely to have higher post-test scores than students in the low-aligned condition, ß=.66, p = .02. We also found a marginally significant interaction between condition and pre-test score, suggesting that students with low prior knowledge of the brace principle may have gained more from the high-aligned condition, ß=.61, p=.06.

As noted previously, the facilitator used a number of gestures during instruction. Embracing the relationship between the classroom and the laboratory, we further investigated the role of gesture during instruction of the brace principle in a one-on-one bridge building lesson. See http://bit.ly/1veIwRt: Comparing Spatial Learning Tools: Spatial Alignment and Gesture During a Bridge Building Lesson for more details.

Analogy is a useful tool for learning in a number of different situations (Gentner, 2010). From language learning (Gentner & Namy, 2006) to elementary engineering (Gentner, Levine, Dhillon, & Poltermann, 2009), analogy can be used to find similarities and differences between situations. According to structure-mapping theory (Gentner, 1983), analogical comparison involves a structural alignment between the two situations, based on finding common relational structure (Gentner & Markman, 1994). This process often leads learners to notice deeper relationships between the two situations, and to notice differences connected to the common relational system.

Implementing structural alignment in education environments could be a particularly beneficial way to help students learn. Research on analogy has revealed important ways in which instructors can help students benefit from analogical comparison (Richland & McDonough, 2010). For instance, if a teacher is trying to build on an old concept in order to teach about a new concept, she might use gesture to show students how to align the situations; or she might set up the two concepts visually in order to help students engage in comparison (Richland et al., 2007). These tools of alignment can highlight the important relationships between concepts. In this research we explore a new method for helping students align two spatial structures: namely, overlaying common structures on top of one another in an explicit form of structural alignment.

In a study at the Museum of Science and Industry in Chicago, IL, we used structural alignment to teach students in grades 3-6 about the importance of triangles for achieving stable structures. We did this in a classroom lab called City Science: Building Bridges, where classrooms of students learned about basic civil engineering principles in the context of building a bridge. During the course of the lab, students were able to build their own bridges out of construction materials called Uberstix.

In order to investigate the potential benefits of structural alignment, a museum staff member (facilitator) taught the students about the importance of triangles in strong bridges using one of two conditions: high-aligned or low-aligned. In both conditions the facilitator presented three components important to truss bridges (bridges made up of a series of triangles): a triangle, a square braced by a diagonal piece (forming a structure made up of two triangles), and a truss. In the high-aligned condition, the triangle was overlayed on the braced square and both the triangle and the braced square were overlayed on the truss. In the low-aligned condition, these alignments were not demonstrated. See Figure 1 for a schematic depiction of the two conditions.

Figure 1. Examples of the high-aligned and low-aligned conditions.

To assess learning (and to control for prior knowledge about triangles in strong structures) we provided students with paper and pencil pretest questions that asked the students to make two structures stronger: a square and a bunk bed. At posttest we asked students to strengthen a rectangle and a skyscraper. We considered the rectangle question (and its pretest control, the square question) to assess near transfer since the students had seen a square braced to create two triangles. We considered the skyscraper question (and its pretest control, the bunk bed question) to assess far transfer, since the facilitator focused on bridges and not on other structures that would also benefit from triangles. See Figure 2 for our pre- and posttest questions.

Figure 2. Near and far transfer pretest and posttest questions.

Preliminary results using logistic regression suggest that alignment may be beneficial during classroom instruction, particularly for students from low SES backgrounds. Overall, students in the high-aligned condition performed significantly better at posttest on the near transfer question, b = .69, p = .03, and marginally better on the far transfer question, b = .50, p = .09, even after controlling for pretest score, grade level, socioeconomic status, and gender. Because of the significant (near transfer) and marginally significant (far transfer) SES effect, we examined results for the two SES groups separately, and found that condition remained an important predictor for the low SES group (near transfer: b = .79, p = .03; far transfer: b = .63, p = .08), but not for the high SES group (near transfer: b = .49, p = .50; far transfer: b = .22, p = .67).

Figure 3. Performance on near and far transfer questions by socioeconomic status (SES). (Y-axis denotes the proportion of students who respond correctly to the question item.)

Another tool of alignment, gesture, may also be useful in a classroom environment. Although we did not explicitly manipulate gesture during the current study, the museum facilitator used gestures to indicate triangles in the various structures he presented. One type of gesture that we were particularly interested in was trace gestures. A trace gesture occurred when the facilitator dragged his index finger along the outline of a triangle. These trace gestures occurred on the triangle alone, on the braced square, and on the truss. Taking advantage of the natural variation in the number of trace gestures the facilitator used in each classroom, we performed a second set of logistic regressions, controlling for the same set of covariates as above. The results show that gesture contributed significantly to students’ learning for both near and far transfer questions, b = .47, p = .008, b = .27, p = .04, respectively. The effect of alignment remained significant for the near transfer question, b = .97, p = .006, and marginal for the far transfer question, b = .51, p = .10. We believe that trace gestures may invite alignment in a different way, by emphasizing the relationships between triangles and their larger structures. Taken together these results suggest that structural alignment is an important learning process for classroom learning, and that it can be accomplished in multiple ways. Further, the use of structural alignment may be particularly important in strengthening learning in low SES students.